大家帮忙看一下这段代码

<P>/*绘制导航图中的方框*/<BR>    void DrawNavigation(AxMap* NavigationMap, AxMap* FullMap)<BR>    {<BR>    Core::Rectangle *rcTrack = new Core::RectangleClass();<BR>    rcTrack = FullMap->Extent;<BR>    Symbol *sym = new SymbolClass();<BR>    sym->SymbolType = SymbolTypeConstants::moFillSymbol;<BR>    sym->OutlineColor = ColorConstants::moBlue;<BR>    sym->Style = FillStyleConstants::moTransparentFill;<BR>    NavigationMap->DrawShape(rcTrack, sym);<BR>    }</P>
<P>运行时没出错，但导航图没画出相应的方框。</P>
<P>请高手指点，谢谢！</P><img src="images/post/smile/dvbbs/em02.gif" /><img src="images/post/smile/dvbbs/em02.gif" /><img src="images/post/smile/dvbbs/em02.gif" />